Mechanical property aspects of diffusion and overlay coatings
The lifetimes of thermomechanical fatigue (TMF) tested nickel-base superalloy single crystal material SRR99 have been found to be reduced for test pieces with a coating applied. Test piece failure is most rapid with a plasma-sprayed CoNiCrAlY (32.5wt% Ni, 20.7 Cr, 8.0 Al, 0.4 Y, remainder Co) coating, compared to the same substrate with a pack-cementation diffusion aluminide coating. Preliminary metallographic characterization of the failure of the CoNiCrAlY is presented, which is of interest in its own right for comparison with service degraded components. Damage accumulation is correlated with applied loading conditions. A description of the TMF degradation of the aluminide coating is given to highlight differences in the test performance of each system.
Bibliographic Reference: Paper presented: High Temperature Surface Engineering, Edinburgh (GB), 23-25 September 1997
Availability: Available from (1) as Paper EN 41089 ORA
Record Number: 199810202 / Last updated on: 1998-02-12
Original language: en
Available languages: en